Answer:
0.033 M
Explanation:
Let's consider the neutralization reaction between NaOH and HCl.
NaOH + HCl → NaCl + H₂O
0.4 L of 0.1 M NaOH were used. The reacting moles of NaOH are:
0.4 L × 0.1 mol/L = 0.04 mol
The molar ratio of NaOH to HCl is 1:1. The reacting moles of HCl are 0.04 moles.
0.04 moles of HCl are in 1.2 L. The molarity of HCl is:
M = 0.04 mol / 1.2 L = 0.033 M
Answer : The pH of a solution is, 7.28
Solution : Given,
Concentration of hydronium ion, 
= 
pH : It is defined as the negative logarithm of hydronium ion concentration or hydrogen ion concentration.
![pH=-\log [H_3O^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH_3O%5E%2B%5D)
Now put the value of hydronium ion concentration in this expression, we get the pH of the solution.
Therefore, the pH of a solution is, 7.28
Answer:
False
Explanation:
Laboratory synthesis of aspirin is done by the acetylation of salicylic acid with the help of acetic anhydride .
As , the acid anhydride is very sensitive to moisture , as it can hydrolyze into two molecules of acids,
Hence , the reaction involving acid anhydride are conducted in anhydrous solvents .
Hence ,
if water is present in the glassware then , some of the acetic anhydride is wasted , Which in turns reduces the yield than that expected .
Answer:
There are two kinds of forces, or attractions, that operate in a molecule—intramolecular and intermolecular. Let's try to understand this difference through the following example.
Explanation:
We have six towels—three are purple in color, labeled hydrogen and three are pink in color, labeled chlorine. We are given a sewing needle and black thread to sew one hydrogen towel to one chlorine towel. After sewing, we now have three pairs of towels: hydrogen sewed to chlorine. The next step is to attach these three pairs of towels to each other. For this we use Velcro as shown above.
So, the result of this exercise is that we have six towels attached to each other through thread and Velcro. Now if I ask you to pull this assembly from both ends, what do you think will happen? The Velcro junctions will fall apart while the sewed junctions will stay as is. The attachment created by Velcro is much weaker than the attachment created by the thread that we used to sew the pairs of towels together. A slight force applied to either end of the towels can easily bring apart the Velcro junctions without tearing apart the sewed junctions.
Exactly the same situation exists in molecules. Just imagine the towels to be real atoms, such as hydrogen and chlorine. These two atoms are bound to each other through a polar covalent bond—analogous to the thread. Each hydrogen chloride molecule in turn is bonded to the neighboring hydrogen chloride molecule through a dipole-dipole attraction—analogous to Velcro. We’ll talk about dipole-dipole interactions in detail a bit later. The polar covalent bond is much stronger in strength than the dipole-dipole interaction. The former is termed an intramolecular attraction while the latter is termed an intermolecular attraction.
The temperature increase when energy in is greater than energy out, and temperature decreases when energy out is than energy in.
